Clinical, microbiological and immunological effects of 3- or 7-day systemic antibiotics adjunctive to subgingival instrumentation in patients with aggressive (stage III/IV grade C) periodontitis: a randomized placebo-controlled clinical trial

Systemic Antibiotic Prophylaxis Adjunctive to Surgical Reconstructive Peri-Implantitis Treatment: A Retrospective Study

AIMS

To evaluate the clinical efficacy of oral systemic antibiotic prophylaxis administered along with the surgical reconstructive peri-implantitis treatment.

METHODS

A total of 49 patients exhibiting 70 implants diagnosed with peri-implantitis underwent a surgical reconstructive peri-implantitis treatment. Of them, 27 patients (38 implants) received a single preoperative shot of antibiotics (2 g amoxicillin; Pre-op), 12 patients (19 implants) were prescribed with postoperative antibiotics for 3 days (500 mg amoxicillin, 3 x day, Post-op), and the remaining 10 patients (13 implants) did not receive any systemic antibiotics (No-Ab). Mean probing depth values (mean PDs; primary outcome), bleeding on probing (BOP), plaque (PI), suppuration (Sup), and deepest PDs values (max PD) were assessed prior to surgery (baseline), after 6 and 12 months. To assess the differences in changes in the clinical parameters, and disease resolution (PD ≤ 5 mm, ≤ 1 BOP site and no Sup) among the groups, logistic regression analyses were performed.

RESULTS

After 12 months, the mean PD reduction amounted to -1.74 ± 1.56 mm, -1.91 ± 1.88 mm, and -1.13 ± 1.05 mm in the No-Ab, Pre-op, and Post-op groups, respectively, with no significant difference detected among the groups. The BOP was reduced in 60%, 59.3%, and 83.3% of the patients after 12 months in the No-Ab, Pre-op, and Post-op groups, respectively, with no significant differences among them. The PI, Sup and max PD reductions were comparable among the groups. Disease resolution after 12 months was established in 61.5%, 73.7%, and 89.5% of patients in the No-Ab, Pre-op, and Post-op groups (No-Ab vs. Pre-op: p = 0.10, No-Ab vs. Post-op: p = 0.40, Pre-op vs. Post-op: p = 0.84).

CONCLUSION

Systemic antibiotic prophylaxis did not improve the clinical outcomes of surgical reconstructive peri-implantitis treatment.

Synergistic Effect of Metronidazole and Chlorhexidine against Porphyromonas gingivalis Growth: An In Vitro Study

Aim: To evaluate the potential synergistic activity of metronidazole (MTZ) and chlorhexidine (CHX) against Porphyromonas. gingivalis (P. gingivalis) growth. Methods: Antimicrobial susceptibility tests of P. gingivalis to MTZ and CHX were performed on in vitro serial 2-fold dilutions of MTZ (from 1 mg/mL to 0.015 mg/mL) and CHX (from 1 mg/mL to 0.03 mg/mL) in thioglycollate medium broth in a 96-well plate. The turbidity of each sample was analyzed by absorbance spectrophotometry at 450 nm wavelengths by using an enzyme-linked immunosorbent assay (ELISA) reader. The MIC50 (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) were assessed. To investigate the potential synergism between MTZ and CHX, bacterial cells were treated with MTZ or CHX, as described above, either alone or in combination. Results: The MIC50 of MTZ was 0.03 mg/mL while that of CHX ranged from 0.12 to 0.06 mg/mL. MTZ and CHX exerted a significant inhibitory effect on P. gingivalis growth in a dose-dependent manner. MTZ at a low and ineffective concentration of 0.015 mg/mL, associated with a suboptimal concentration of CHX (0.03 mg/mL), exhibited a significant synergistic inhibitory effect on bacterial growth (50% inhibition vs. control) (p < 0.001), and the effect was more remarkable with 0.06 mg/mL CHX (75% inhibition vs. control). Conclusions: CHX and MTZ showed a significant synergistic effect against P. gingivalis growth. A non-effective concentration of MTZ (0.015 mg/mL) combined with suboptimal concentrations of CHX (0.03 mg/mL and 0.06 mg/mL) were related to a 50% growth in the inhibition and 99.99% death of P. gingivalis, respectively. The applicability of the clinical use of these concentrations should be tested in randomized controlled trials.

Decision-making on systemic antibiotics in the management of periodontitis: A retrospective comparison of two concepts

AIM

To retrospectively compare two approaches for the adjunctive use of systemic antibiotics in non-surgical periodontal therapy: one based on the detection of Aggregatibacter actinomycetemcomitans (Aa) and the other on age and severity of periodontitis (Age & PPD). We also assessed the additional benefit of antibiotics in reducing the need for further surgical therapy in each group.

MATERIALS AND METHODS

Patients of the Department of Periodontology, Goethe University Frankfurt, Germany, were screened for microbiological testing between 2008 and 2018. Patients were categorized by their microbiological result (Aa+/-) and demographic/clinical data (Age & PPD+/-). Agreement on antibiotic indication was tested. The clinical evaluation focussed on teeth with probing pocket depths (PPDs) ≥ 6 mm.

RESULTS

Analysis of 425 patients revealed 30% categorized as Age & PPD+ and 34% as Aa+. Sixty-three percent had consistent antibiotic recommendations (phi coefficient 0.14, p = .004). Patients in the Age & PPD+ group receiving antibiotics showed the most substantial reduction in the number of teeth with PPD ≥ 6 mm after non-surgical periodontal therapy.

CONCLUSIONS

Both strategies resulted in a significant clinical improvement compared with those without antibiotic treatment and restricted antibiotic use similarly, but targeted different patient groups. Younger individuals with severe periodontitis benefited most from antibiotics, reducing the need for additional surgeries. The study was registered in an international trial register (German Clinical Trial Register number DRKS00028768, registration date 27 April 2022, https://drks.de/search/en/trial/DRKS00028768).

Based on network pharmacology and molecular docking to explore the potential mechanism of shikonin in periodontitis

OBJECTIVES

To investigate the potential mechanisms of shikonin in preventing and treating periodontitis using network pharmacology and molecular docking methods.

MATERIALS AND METHODS

The targets of shikonin were obtained in TCMSP and SEA databases, and targets of periodontitis were gathered from the OMIM, GeneCards and Drugbank Databases. The intersecting targets were entered into the DAVID database to obtain the relevant biological functions and pathways by GO and KEGG enrichment analysis. The obtained targets were analysed the protein-protein interaction (PPI) in STRING platform. In Cytoscape 3.8.0, the network analysis function with the MCODE plug-in were used to obtain the key targets, of shikonin and periodontitis. Molecular docking and molecular dynamics simulation (MD) were used to assess the affinity between the shikonin and the key targets.

RESULTS

Shikonin was screened for 22 targets and periodontitis was screened for 944 targets, the intersecting targets were considered as potential therapeutic targets. The targets played important roles in cellular response to hypoxia, response to xenobiotic stimulus and positive regulates of apoptotic process by GO enrichment analysis. 10 significant pathways were analyzed by KEGG, such as human cytomegalovirus infection and PI3K-Akt signaling pathway, etc. Cytoscape software screened the key genes including AKT1, CCL5, CXCR4, PPARG, PTEN, PTGS2 and TP53. Molecular docking and MD results showed that shikonin could bind stably to the targets.

CONCLUSIONS

The present study enriched the molecular mechanisms in periodontitis with shikonin, providing potential therapeutic targets for periodontitis.

The adjunctive use of antimicrobial photodynamic therapy, light-emitting-diode photobiomodulation and ozone therapy in regenerative treatment of stage III/IV grade C periodontitis: a randomized controlled clinical trial

OBJECTIVES

To assess the short-term efficacy of multiple sessions of antimicrobial photodynamic therapy (aPDT), light-emitting-diode (LED) photobiomodulation, and topical ozone therapy applications following surgical regenerative treatments on clinical parameters, patient-centered outcomes, and mRNA expression levels of VEGF, IL-6, RunX2, Nell-1, and osterix in gingival crevicular fluid samples in patients with stage III/IV, grade C periodontitis.

MATERIALS AND METHODS

Forty-eight systemically healthy patients were assigned into four groups to receive adjunctive modalities with regenerative periodontal surgical treatment. A 970 ± 15 nm diode laser plus indocyanine-green for aPDT group, a 626 nm LED for photobiomodulation group, and topical gaseous ozone were applied at 0, 1, 3, and 7 postoperative days and compared to control group. The clinical periodontal parameters, early wound healing index (EHI), and postoperative patients' morbidity were evaluated. The mRNA levels of biomarkers were assessed by real-time polymerase chain reaction.

RESULTS

No significant difference in the clinical parameters except gingival recession (GR) was identified among the groups. For group-by-time interactions, plaque index (PI) and probing pocket depths (PD) showed significant differences (p = 0.034; p = 0.022). In sites with initial PD > 7 mm, significant differences were observed between control and photobiomodulation groups in PD (p = 0.011), between control and aPDT, and control and photobiomodulation groups in CAL at 6-month follow-up (p = 0.007; p = 0.022). The relative osterix mRNA levels showed a statistically significant difference among the treatment groups (p = 0.014).

CONCLUSIONS

The additional applications of aPDT and LED after regenerative treatment of stage III/IV grade C periodontitis exhibited a more pronounced beneficial effect on clinical outcomes in deep periodontal pockets.

A Low-Cost Protocol Using the Adjunctive Action of Povidone-Iodine Irrigations and Sodium Hypochlorite Rinsing Solution in Step 2 of Periodontal Therapy for Patients with Stage III-IV Periodontitis: A Single-Blind, Randomized Controlled Trial

In severe stages of periodontitis, conventional periodontal therapy and maintenance care are usually insufficient due to the viral and bacterial etiology; thus, a mechanical approach alone may not be sufficient to eliminate a substantial portion of subgingival pathogens, especially in deep periodontal sites. Background and Objectives: This single-blind, randomized clinical trial aimed to compare the clinical and microbiological efficacy of a low-cost protocol using povidone-iodine and sodium hypochlorite formulations as adjuncts to non-surgical therapy for patients with stage IV periodontitis when compared with chlorhexidine, the most commonly employed substance to date for antimicrobial regimens in periodontal therapy. Materials and Methods: Forty-five patients were randomly divided into two groups: control (subgingival instrumentation, chlorhexidine-assisted) and test (antiviral medication, subgingival instrumentation with povidone-iodine, sodium hypochlorite rinsing solution, and antibiotics). Clinical measurements and microbiological analyses were performed at baseline and after three months. Results: After three months, notable differences were found in the bacterial detection scores for Porphyromonas gingivalis (a significant reduction in detection frequency was observed in the test compared to the control (p = 0.021)), and there were significant reductions in detection in the test group for Tannerella forsythia and Treponema denticola, showing undetectable levels (p < 0.0001 for both). In the test group, the pocket probing depth median value was reduced significantly (p = 0.0005); similarly, bleeding on probing showed a marked decrease (p < 0.0001). However, changes in clinical attachment loss and full-mouth plaque score were not statistically significant. Conclusions: Using the proposed protocol, substantial improvements in clinical and microbiological parameters were obtained when compared with the current antimicrobial recommendations.

Antibiotic resistance in the microbiota of periodontitis patients: an update of current findings

Systemic antibiotics are an effective adjunct in the treatment of periodontitis, but their judicious use is necessary as antimicrobial resistance is a growing global concern. This review aims to explore the current understanding and insight related to antibiotic resistance in the subgingival microbiota of periodontitis patients. A search of MEDLINE (PubMed) was carried out from 1 January 2012 to 25 November 2021 for studies related to antibiotic resistance in periodontitis patients. Of the 90 articles identified, 12 studies were selected for inclusion. A significant incidence of antibiotic resistant isolates was reported for Porphyromonas gingivalis, Prevotella intermedia, Prevotella denticola, Prevotella melaninogenica, Fusobacterium nucleatum, Tanerella forsythia, Aggretibacter actinomycetemcomitans, Streptococcus constellatus, Streptococcus intermedius, and Parvimonas micra, but resistance to specific antibiotics did not reach above 10% of isolates in most studies except for amoxicillin resistance in Aggretibacter actinomycetemcomitans. The highest frequency of resistance across all bacterial species was for amoxicillin, clindamycin, and metronidazole. However, resistance patterns were widely variable across geographical locations, and the high heterogeneity between antibiotic-resistant isolates across studies precludes any clinical recommendations from this study. Although antibiotic resistance has yet to reach critical levels in periodontitis patients, an emphasis on antibiotic stewardship interventions such as point-of-care diagnostics and education for key stakeholders is needed to curb a growing problem.

Changes in cuproptosis-related gene expression in periodontitis: An integrated bioinformatic analysis

Periodontitis causes inflammatory destruction of tooth-supporting tissues; however, the complex mechanism underlying its etiology remains unclear. Cuproptosis is a type of cell death caused by an imbalance in intracellular copper homeostasis that leads to excess copper. However, changes in the expression and biological function of cuproptosis-related genes (CRGs) in periodontitis are not yet fully understood. This study investigated the comprehensive effects of differentially expressed CRGs (DE-CRGs) on periodontitis via bioinformatic analysis. Nine DE-CRGs were discovered using normal and periodontitis gingival samples, and single-cell RNA sequencing data were analyzed to identify them changes in diverse cell clusters. We then detected the correlation between DE-CRGs and immune infiltration, immune factors, mitochondrial dysfunction, diagnostic efficacy, and predicted drugs. Moreover, changes of DE-CRG in whole periodontitis tissue and a human gingival fibroblast cell line (HGF-1) were confirmed and copper content changes in HGF-1 cells were investigated. Most DE-CRG expression trends were reversed between the periodontal tissues and cell clusters, which may be related to the proportion of cell clusters changes caused periodontitis. Furthermore, most DE-CRG trends in periodontitis cell clusters were inconsistent with the effects of cuproptosis. In HGF-1 cells treated with Porphyromonas gingivalis lipopolysaccharide (Pg-LPS), the intracellular copper content increased by more than threefold, indicating that although some periodontitis cells had excess copper, the amount may not have been sufficient to trigger cuproptosis. Additionally, DE-CRGs were closely associated with multiple biological functions, antibiotic drugs, and natural herbal medicines. Our findings may provide an overview of DE-CRGs in the pathogenesis and treatment of periodontitis.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2022 dental literature to briefly touch on several topics of interest to modern restorative dentistry. Each committee member brings discipline-specific expertise in their subject areas that include (in order of the appearance in this report): prosthodontics; periodontics, alveolar bone, and peri-implant tissues; dental materials and therapeutics; occlusion and temporomandibular disorders; sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence the daily dental treatment decisions of the reader with an emphasis on innovations, new materials and processes, and future trends in dentistry. With the tremendous volume of literature published daily in dentistry and related disciplines, this review cannot be comprehensive. Instead, its purpose is to update interested readers and provide valuable resource material for those willing to subsequently pursue greater detail on their own. Our intent remains to assist colleagues in navigating the tremendous volume of newly minted information produced annually. Finally, we hope that readers find this work helpful in managing patients.

Clinical benefits of systemic amoxicillin/metronidazole may depend on periodontitis stage and grade: An exploratory sub-analysis of the ABPARO trial

AIM

Assessment of treatment response after systemic amoxicillin/metronidazole adjunctive to subgingival instrumentation (SI) according to stages and grades of the 2018 classification of periodontal diseases.

MATERIALS AND METHODS

We carried out exploratory re-analysis of the placebo-controlled, multi-centre ABPARO trial (52; 45/60 years of age; 205 males, 114 active smokers). Patients were randomized to SI with systemic amoxicillin 500 mg/metronidazole 400 mg (three times a day for 7 days, n = 205; ANTI) or placebo (n = 200; PLAC) and maintenance therapy every 3 months. Patients were reclassified according to the 2018 classification (stage/extent/grade). Treatment effect was the percentage of sites per patient with new attachment loss ≥1.3 mm (PSAL ≥ 1.3 mm) at 27.5 months post-baseline/randomization.

RESULTS

All patients were assigned according to the stage (n = 49 localized stage III, n = 206 generalized stage III, n = 150 stage IV). Because of missing radiographs, only 222 patients were assigned to grades (n = 73 B, n = 149 C). Treatment (PLAC/ANTI) resulted in PSAL ≥ 1.3 mm (median; lower/upper quartile) in localized stage III (PLAC: 5.7; 3.3/8.4% vs. ANTI: 4.9; 3.0/8.3%; p = .749), generalized stage III (8.0; 4.5/14.3% vs. 4.7; 2.4/9.0%; p < .001), stage IV (8.5; 5.1/14.4% vs. 5.7; 3.3/10.6%; p = .008), grade B (4.4; 2.4/6.7% vs. 3.6; 1.9/4.7%; p = .151) and grade C (9.4; 5.3/14.3% vs. 4.8; 2.5/9.4%; p < .001).

CONCLUSIONS

In generalized periodontitis stage III/grade C, a clinically relevant lower percentage of disease progression after adjunctive systemic amoxicillin/metronidazole was observed compared to placebo (PLAC: 9.7; 5.8/14.3% vs. ANTI: 4.7; 2.4/9.0%; p < .001).

Long-term changes in the subgingival microbiota in patients with stage III-IV periodontitis treated by mechanical therapy and adjunctive systemic antibiotics: A secondary analysis of a randomized controlled trial

AIM

To explore whether adjunctive antibiotics can relevantly influence long-term microbiota changes in stage III-IV periodontitis patients.

MATERIALS AND METHODS

This is a secondary analysis of a randomized clinical trial on periodontal therapy with adjunctive 500 mg amoxicillin and 400 mg metronidazole or placebo thrice daily for 7 days. Subgingival plaque samples were taken before and 2, 8, 14 and 26 months after mechanical therapy. The V4-hypervariable region of the 16S rRNA gene was sequenced with Illumina MiSeq 250 base pair paired-end reads. Changes at the ribosomal sequence variant (RSV) level, diversity and subgingival-microbial dysbiosis index (SMDI) were explored with a negative binomial regression model and non-parametric tests.

RESULTS

Overall, 50.2% of all raw reads summed up to 72 RSVs (3.0%) that were generated from 163 stage III-IV periodontitis patients. Of those, 16 RSVs, including Porphyromonas gingivalis, Tannerella forsythia and Aggregatibacter actinomycetemcomitans, changed significantly over 26 months because of adjunctive systemic antibiotics. SMDI decreased significantly more in the antibiotic group at all timepoints, whereas the 2-month differences in alpha and beta diversity between groups were not significant at 8 and 14 months, respectively.

CONCLUSIONS

Mechanical periodontal therapy with adjunctive antibiotics induced a relevant and long-term sustainable change towards an oral microbiome more associated with oral health.

Europe's contribution to the evaluation of the use of systemic antimicrobials in the treatment of periodontitis

This narrative review celebrates Europe's contribution to the current knowledge on systemically administered antimicrobials in periodontal treatment. Periodontitis is the most frequent chronic noncommunicable human disease. It is caused by dysbiotic bacterial biofilms and is commonly treated with subgingival instrumentation. However, some sites/patients do not respond adequately, and its limitations and shortcomings have been recognized. This has led to the development of alternative or adjunctive therapies. One is the use of antimicrobials to target bacteria in subgingival biofilms in the periodontal pocket, which can be targeted directly through the pocket entrance with a locally delivered antibiotic or systemically by oral, intravenous, or intramuscular methods. Since the early 20th century, several studies on systemic antibiotics have been undertaken and published, especially between 1990 and 2010. Europe's latest contribution to this topic is the first European Federation of Periodontology, S3-level Clinical Practice Guideline, which incorporates recommendations related to the use of adjuncts to treat stage I-III periodontitis. Understanding the etiopathogenesis of periodontal diseases, specifically periodontitis, has influenced the use of systemic periodontal antibiotic therapy. Randomized clinical trials and systematic reviews with meta-analyses have demonstrated the clinical advantages of adjunctive systemic antimicrobials. However, current recommendations are restrictive due to concerns about antibiotic misuse and the increase in microbial antibiotic resistance. European researchers have contributed to the use of systemic antimicrobials in the treatment of periodontitis through clinical trials and by providing rational guidelines. Nowadays, European researchers are exploring alternatives and directing clinical practice by providing evidence-based guidelines to limit the use of systemic antimicrobials.

Systemic Antibiotics and Chlorhexidine Associated with Periodontal Therapy: Microbiological Effect on Intraoral Surfaces and Saliva

The effect of systemic antibiotics on the microbial profile of extracrevicular sites after periodontal treatment is currently the subject of research. This study evaluated the microbiological effects on different oral cavity sites of scaling and root planing (SRP) combined with antimicrobial chemical control in the treatment of periodontitis. Sixty subjects were randomly assigned to receive SRP alone or combined with metronidazole (MTZ) + amoxicillin (AMX) for 14 days, with or without chlorhexidine mouth rinse (CHX) for 60 days. Microbiological samples were evaluated by checkerboard DNA-DNA hybridization until 180 days post therapy. The adjunctive use of antibiotics plus CHX significantly reduced the mean proportions of red complex species from subgingival biofilm and saliva (p < 0.05). Furthermore, the analysis of all intraoral niches showed a significantly lower mean proportion of the red complex species in the same group. In conclusion, the concomitant use of antimicrobial chemical control (systemic and local) demonstrated a beneficial effect on the composition of the oral microbiota.

Additional benefit of systemic antibiotics in subgingival instrumentation of stage III and IV periodontitis with Aggregatibacter actinomycetemcomitans: A retrospective analysis

AIM

To evaluate subgingival instrumentation (SI) in periodontitis stage III and IV, grade B and C with systemic antibiotics (AB) only after detection of Aggregatibacter actinomycetemcomitans.

MATERIALS AND METHODS

Patients of the Department of Periodontology of Goethe University Frankfurt/Germany were screened for microbiological testing between 2008 and 2018. All patients with aggressive and generalized severe chronic periodontitis were tested. In case of positive subgingival A. actinomycetemcomitans tests, SI was combined with AB; in all other cases it was not (nAB). Clinical examinations were performed before (T0), 12.4 (9.4/15.1) weeks after SI (T1), and at the last supportive periodontal care (T2; 3.1 [1.4/5.5] years after T1). Results at T1/T2 were assessed as "treat-to-target" endpoint (≤4 sites with probing pocket depths ≥5 mm).

RESULTS

Four-hundred and twenty-five patients (280 stage III/145 stage IV, 95 grade B/330 grade C) provided complete data (AB 144/nAB 281) for T0 and T1, and 332 (AB 121/nAB 211) for T2. At T1/T2, AB resulted in 53 (37%)/76 (63%) patients with "treat-to-target" endpoint, and nAB in 76 (27%)/91 (43%) (p = .038/.001).

CONCLUSIONS

In periodontitis stage III and IV, grade B and C with subgingival A. actinomycetemcomitans infection, SI with AB resulted in higher rate of "treat-to-target" endpoint than exclusive SI in patients without the infection.

Coaxial electrospun nanofibers as drug delivery system for local treatment of periodontitis

OBJECTIVES

The aim of the present study was to prepare resorbable polylactide fibers for periodontitis treatment using coaxial electrospinning to optimize the release of metronidazole (MNA) by reducing the initial burst effect.

METHODS

Poly(L-lactide-co-D,L-lactide) (PLA) fibers mats with different distributions of metronidazole (MNA) were manufactured by coaxial electrospinning (COAX). By COAX spinning the central core of the fiber was enriched with 40% MNA (m/m), while the sheath of the fiber consisted of PLA only (test group). In contrast, fibers of the control group were prepared by conventional electrospinning with the same amount of MNA but with a homogenous drug distribution (HDD - homogenously distributed drug). The release of MNA was determined by analyzing aliquots from the fiber mats using UV-VIS spectroscopy. Agar diffusion tests were carried out to determine the antibacterial effect on periodontopathogenic bacteria. Biocompatibility was tested in direct contact to human gingival fibroblasts (HGF) for two days.

RESULTS

The COAX mats showed a retarded drug release compared to the conventional HDD fibers. After 24 h, 64% of total MNA was released cumulatively from the COAX fibers while 90% of the MNA was released from the HDD fibers (controls). The antibacterial effect of COAX fibers was significantly higher after 24 h compared to the HDD fibers. Cell cultivation revealed significant higher numbers of vital cells among the COAX mats.

SIGNIFICANCE

COAX fibers showed improved sustained MNA release compared to conventional fibers and can be seen as potential drug delivery systems in local periodontitis treatment.